Arc lamp



y 1931. A. F. MARTIN 1,814,321

ARC LAMP Filed Feb. 9, 1925 2 Sheets-Sheet 1 July 14, -l931. A. F.MARTIN 1,814,321

ARC LAMP Filed Feb. 9, 1925 2 Sheets-Sheet -2 Patented July 14, 1931UNITED STATES PATENT OFFICE ALLAN F. MARTIN, OF ROCHESTER, NEW YORK,ASSIGNOR TO BAUSCH & LOMB OPTICAL COMPANY, OF ROCHESTER, NEW YORK, ACORPORATION OF NEW YORK ARC LAMP Application filed February The presentinvention relates to arc lamps, and has for its object to provideimprovements in lamps of this kind, particularly with respect to thefeeding means for the electrodes.

Another object of the invention is to provide a continuous and positivedriving connection for the electrodes together with improved operatingmeans for advancing the in same in the direction desired.

Another object of the invention is to provide an arc lamp adapted to beeconomically constructed and operated, having cooperating actuatingdevices for feeding the carbons, arranged to operate independently andpermitting the driven parts to be returned to initial starting positionwithout interfering with the driving or actuating devices.

To these and other ends the invention resides in certain improvementsand combinations of parts, all as will be hereinafter more fullydescribed, the novel features being pointed out in the claims at the endof the specification.

In the drawings Figure 1 is a side elevation of a machine embodying oneform of the invention;

Figure 2 is a sectional elevation taken on line 2a2t of Figure 3;

Figure 3 is a top plan view of the lamp;

Figure 4 is a sectional plan taken on line 4a4la of Figure 2;

Figure 5 is a fragmentary sectional plan taken on line 5a-5a of Figure2;

Figure 6 is a sectional plan taken on line 6a-6w of Figure 2, and

Figure 7 is a diagrammatic view illustrating the continuous chain drive.shown in Figure 2.

Similar reference numerals throughout the several views indicate thesame parts.

The present are lamp is shown in connection with a projection apparatusfor microscopic projection work whereby to illustrate one of a number ofdifferent kinds of machines with ,which the invention may be used. Theprojection apparatus is illus' trated generally at 10 and includes aframe 11 and an upstanding bracket 12 thereon 9, 1925. Serial No. 7,796.

box having a chimney with a circuitous paseageway 21 for the escape ofthe products of combustion of the burning electrodes and also havingadjustable closures or windows 22 through which the burning carbons maybe viewed and also through which air may be admitted in addition to thesupply passing through the openings 18a and 19.

he electrodes and the feeding devi es therefor are mounted upon a pairof spaced plates or frame members 23 and 2 1, the upper left handcorners of which project into the lamp box as shown in Figure 2, beingsuitably connected therewith and supported thereon preferably by meansof the downwardly projecting lugs 25 and the screws 26 extending intosaid plates.

The horizontally disposed electrode 17 is removably attached to asuitable holder 27 and the vertical electrode 18 to a similar holder 28,these holders being slidably disposed preferably upon a pair ofhorizontal guides 29 and a pair of Vertical guides 30,

respectively. The outer ends of the guide rods 29 are suitably connectedwith a 1nember 31 forming a spacer between the plates 23 and 24 and thevertical guide rods have their outer ends suitably connected with amember 32 forming a spacer between the lower edges of the plates, asshown in Figure 2. 7 their inner or adjacent ends anchored in a block 33forming a spacer betw en the upper left hand corners of said plates, theblock 33 being preferably constructed of a suitable heat resistingmaterial, such as fireclay, on account of its proximity to the arc, theblock being suitably held preferably by a pin 34, the ends of which aresupported by the side plates 23 and 24.

The means for advancing the holders 2? Both sets of guide rods have and28 preferably comprises a flexible operating member in the form of acontinuous chain or like connection, with means for positively drivingthe same which will hereinafter be described. The chain or flexibleconnection is extended over a series of pulleys or rollers constitutingthe upper and lower rollers 36 and 37, respectively, and a pair ofintermediate rollers 38 and 39 adjaccntly mounted upon a support 40which is suitably secured between the plates 23 and 24 as shown inFigure 5. The rollers 36 and 37 are carried by the transverselyextending supports 41 and 42, respectively, the ends of which aresuitably secured upon the side plates 23 and 24. The chain is directlyconnected with the carbon holders 27 and 28, as by means of the studs43, so that it will advance each at the same rate of speed and therebymaintain their free ends at the desired distance apart. The chain isalso carried over a driving sprocket indicated at 44 which has a hub 45rigidly connected with a driving shaft 46 which may be driven by anysuitable means. The driving shaft 46 is preferably driven by a suitableclock mechanism disposed in a casing 47 which is preferably mounted uponthe outer face of the plate 24 and secured thereon by the screws 48. Theclock is provided with the usual winding stem 49 and lever 50 forregulating its speed. The clock may be conveniently started orstopped bypressing a plunger 51 which is spring returned and provided with alateral extension, not shown, for engaging the teeth of the balancewheel to both start and stop the same as desired. The shaft 46 is soconnected with the clock driving mechanism as to be revoluble in adirection reverse to the direction in which it is normally drivenwithout interfering with the operation of the clock, whereby theoperator by turning the hand wheel 52 counterclockwise may reverse themovement of the chain and return the holders 27 and 28 to their initialstarting position as shown in Figure 2.

In addition to the clock mechanism for positively driving the continuouschain 35 I provide an actuating spring 53 preferably wound upon asupport 54'and having an arm-like portion 55 looped at 56 to looselyengage a stud 57 projecting from the holder 28 carrying the verticallydisposed electrode 18, said'looped end being free to slide on the stud57 as the holder 28 is moved upwardly with the electrode. The spring 53tends to raise the arm 55 thereby acting to lift the holder 28, which byreason of the fact that it is connected with the chain exerts a pullthereon in an upward direction, thereby cooperating with the clockmechanism in advancing the electrodes and thus reducing the load on theclock mechanism. The spring not only serves as a direct means forexerting a lifting force upon the holder 28 and the electrode carriedthereby, but at the same time assists in advancing the holder 27,through the pull which it exerts upon the chain in the direction of itsmovement.

WVhile the clock spring may be made strong enough to advance theelectrodes independently of any other lifting mechanism it is desirableto use a relatively small clock and provide means adapted to cooperatetherewith in moving the parts in the direction desired. As theelectrodes are gradually burned away, the load becomes lighter thenearer the holders approach their destination and likewise the drivingsprings become weaker as they unwind, whereby the proportion of liftingpower to the load to be lifted remains substantially constant.

Connected with the holders 27 and 28, as indicated at 57a in Figure 6,are flexible cables 58 and 59, the outer ends of which are connectedwith binding posts 60 and 61, respectively, which are suitably insulatedfrom the plates 23 and 24 and preferably constitute extensions on thespacing members 31 and 32. Any suitable electric current supply source,not shown, may be provided and connected with said binding posts throughthe medium of suitable conductors.

The means by which reversal of the shaft 46 is effected withoutreversing the clock mechanism is shown in Fig. 3 along with certain ofthe operating parts of the clock. These include the main spring 62 onthe winding shaft 63 and the driving gear 64 on the same shaft. Thedriving gear engages a pinion loosely mounted upon the shaft 46 whichcomprises the spaced end plates 65 and 66 and the pins 67 extendingtherebetween The plate 66 is connected with and drives a gear 68, alsoloose on shaft 46, and which in turn drives the remaining gears of theoperating parts, (not shown) for actuating the escapement wheel of theclock. The driving means for the shaft 46 comprises a clutch thereonfrictionally driven by the plates 65, the clutch embodying a bowed ordish-like spring 69 urged into engagement with said plateby a collar 70fixed on the shaft 46. The pressure exerted by the spring and theresultant friction afforded by the parts associated therewith issufficient to drive the shaft 46 andthe chain arranged to be driventhereby. However, in manually reversing the shaft as by turning the handwheel 52 to reverse the movement ofthe chain, the friction exerted bythe clutch on the plate 65 is not suflicient to cause reverse rotationof the driving gear 64 against the action of the main spring 62.Consequently the clock .mechanism is not reversed and is in no wayinterfered with by manual rotation of the shaft 46 when operating it toreturn the carbon holders to their extreme outer position.

I claim as my invention:

1. In an arc lamp, a frame, a pair of electrodes mounted for iovementupon the frame one toward another, a flexible driving connection forsimultaneously advancing the electrodes toward each other, andindependent devices for driving said connection, one including a rotarypart for advancing the connection and the other a yieldable elementarranged to urge the connection in the direction of its movement by therotary part.

2. In an arc lamp, a frame including guides, holders slidably mountedupon the guides, electrodes carried by the holders, a series of rollersupon the frame, a flexible operating connection extending over therollers and engaging the holders, and independent operating devices forsaid connection cooperating to effect advancement of the holders towarda common point, one of said devices including a rotary driving part forthe connection and the other comprising an arm with. means for swingingit about a point spaced from the connection.

3. In an arc lamp, a frame including guides, holders slidably mountedupon the guides, electrodes carried by the holders, a series of rollersmounted upon the frame, a flexible operating connection extending overthe rollers and connected with the holders, a clock mechanism adapted todrive said connection, and spring means cooperating with the clockmechanism and operating independently thereof to drive said connection.

4. In an arc lamp, a frame comprising spaced connected plates, angularlydisposed guides mounted between said plates, separate holders mounted totravel upon the guides, electrodes carried by the holders, a continuouschain disposed between the plates to advance the holders toward a commonpoint, and separate devices for driving the chain operable upon thelatter at different points in its path of movement, one of said devicesincluding a power driven element and the other comprising a springcoiled upon a support and having a swingingly mounted operating port-ionconnecting with the chain.

5. In an arc lamp, a frame comprising spaced connected plates, angularlydisposed guides mounted between said plates, separate holders mounted totravel upon the guides, electrodes carried by the holders, a. flexibleoperating connection for the holders disposed between the plates andadapted to advance the holders toward a common point, clock mechanismoperating upon said connection to effect movement of the holders, amember carried by one of the holders and a swingingly mounted springactuated arm having its free end in sliding engagement with said memberand operating thereon to assist the clock mechanism in advancement ofsaid flexible operating connection.

6. In an arc lamp, a frame including guides, holders slidably mountedupon the guides, electrodes carried by the holders, a series of rollersupon the frame, a flexible ope-rating connection extending over therolhers and engaging the holders, driving means for the connection, andauxiliary driving means for the connection comprising a springoperatively associated with one of the holders and tending to lift thesame.

7. In an an: lamp, a frame including guides, holders slidably mountedupon the guides, electrodes carried by the holders, a series of rollersupon the frame, a flexible operating connection extending over therollers and engaging the holders, driving means for said connection, anda spring including an extended arm-like portion engaging one of theholders and cooperating with the driving means to advance saidconnection.

8. In an arc lamp, 2. frame, a pair of electrodes one of which ishorizontally and the other vertically disposed upon the frame formovement toward a common point, holders for said electrodes, a.plurality of rollers carried by the frame, a flexible driving elementextending over the rollers and operatively engaging said holders,actuating means for said driving element, and a spring including anextended arm-like portion secured to the frame at one end and having itsother end connected with and free to move relative to the holder of thevertically disposed electrode.

9. In a device of the class described, a lamp housing comprising a bodyhaving a portion adapted for connection with a projection apparatus,said body being provided with a chimney and having openings below thechimney in its bottom and one of its vertical walls, a frame dependingfrom and supported by the housing, angularly (lisposed guides carried bythe frame, holders mounted for travel upon the guides toward thehousing, angularly disposed electrodes carried by the holders andprojecting through said openings into the housing and means foradvancing the holders toward the housing.

10. In an arc lamp, a frame, holders reciprocally mounted upon theframe, electrodes carried by the holders, a flexible connection on theframe for moving the holders back and forth thereon, a clock mechanismincluding a train of gears and an arbor, a driving device for the arbordriven by one of the gears, said arbor being reversible withoutreversing the movement of the gears, and means actuated by the arbor foroperating said flexible connection, reversal of the arbor serving toeffect reverse movement of the connection and the holders op eratedthereby.

11. In an arc lamp, a frame, spaced holders reciprocally mounted uponthe frame each arranged to support an electrode, a flexible operatingconnection arranged to reciprocate the holders, a clockmechanismincluding a train of gears and an arbor on which one of thegears is mounted to ro-' tate, driving means for the arbor arranged tobe driven by said last gear, the arbor being reversible Withoutreversing said gear, and

' means on the arbor arranged to drlve said flexible connection,reversal of the arbor serving to ellect reverse movement of theconnection.

12. In an arc lamp, a frame, spaced hold- 15 ers reciprocally mountedupon the frame, a reversible operating device for said holders, a clockmechanism including a train of gears and an arbor on which one of thegears is mounted to rotate, driving means for the 2- arbor arranged tobe driven by said last mentioned gear, said driving means permittingreverse movement of the arbor Without reversal of said gear and means onthe arbor for driving said reversible operating device.

- 13. In an arc lamp, a frame, holdersreciprocally mounted upon theframe, electrodes carried by the holders, a flexible con nection on theframe for moving the holders so back and forth thereon, a clockmechanism including a train of gears and an arbor, a driving device forthe arbor driven by one of the gears said arbor being reversiblewithoutreversing the movement of the gears, 3 means actuated by the arbor foroperating said flexible connection, reversal of the arbor serving toeffect reverse movement of the connection and the holders operatedthereby, and yieldable means supplementing 40 the clock mechanism andtending to constantly move the connection in the direction in which itis moved by theclock mechanism to advance the electrodes one towardanother.

ALLAN F. MARTIN.

